In a population-based study reported in the Journal of Clinical Oncology, Chehab et al found that survivors of childhood cancer were at significantly increased risk of infections resulting in hospitalization vs comparators without cancer.
The study involved children and adolescents born in Washington state diagnosed with cancer at age < 20 years between 1982 and 2008 who survived for at least 5 years after their diagnosis. Survivors were randomly matched 1:10 by sex and birth year to comparators without cancer. The primary outcome measure was incidence of any infection associated with a hospitalization using diagnostic codes from state hospital discharge records.
A total of 382 of 3,152 survivors and 771 of 31,519 comparators were hospitalized for infection.
The incidence rate per 1,000 person-years for all hospitalized infections beginning 5 years after cancer diagnosis was 12.6 (95% confidence interval [CI] = 11.4–13.9) among survivors vs 2.4 (95% CI = 2.3–2.6) among comparators, yielding an incidence rate ratio of 5.1 (95% CI = 4.5–5.8). Incidence rate ratios were 7.5 (95% CI = 6.5–8.7) for 1,244 survivors of hematologic malignancies and 3.6 (95% CI = 3.0–4.3) for 1,908 survivors of nonhematologic malignancies.
During the 5- to 10-year period after diagnosis, the incidence rate per 1,000 person-years was 18.1 (95% CI = 15.9–20.5) among survivors vs 2.3 (95% CI = 2.1–2.6) among comparators, with incidence rates of 30.3 (95% CI = 26.0–35.5) for survivors of hematologic malignancies and 10.1 (95% CI = 8.2–12.6) for survivors of nonhematologic malignancies. At > 10 years after diagnosis, incidence rates were 8.3 (95% CI = 7.0–9.7) vs 2.5 (95% CI = 2.3–2.8), with incidence rates of 9.2 (95% CI = 7.2–11.8) and 7.6 (95% CI = 6.1–9.5) for survivors of hematologic and nonhematologic malignancies, respectively.
Bacterial infections were the most common infections resulting in hospitalization among survivors of both hematologic and nonhematologic malignancies; however, the incidence rate ratio was greatest for fungal infections in both groups (25.2, 95% CI = 14.7–43.2, and 10.2, 95% CI = 5.5–18.9, respectively) followed by bacterial infections (10.7, 95% CI = 8.3–13.7, and 4.0, 95% CI = 3.0–5.5).
In an analysis of potentially vaccine-preventable infections, survivors had a greater risk of hospitalization for infection (IRR = 13.1, 95% CI = 7.2–23.9).
The investigators concluded, “Infectious complications continue to affect survivors of childhood cancer many years after initial diagnosis. Future studies are needed to better understand immune reconstitution to determine specific factors that may mitigate this risk.”
Jenna Rossoff, MD, of the Ann & Robert H. Lurie Children’s Hospital of Chicago, Northwestern University Feinberg School of Medicine, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by Alex’s Lemonade Stand Foundation for Childhood Cancer and others. For full disclosures of the study authors, visit ascopubs.org.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.